Calcium chloride to lower PH

crsublette

coyotes call me Charles
Joined
Oct 23, 2011
Messages
2,678
Reaction score
1,100
Location
Dalhart Texas
Hardiness Zone
6a
Yep, the calcium is a mineral that does increase the GH test value. Depending on how accurately you are viewing the liquid pH test kit, I think 8.8 pH is within a good range of variance. I wouldn't be concerned until it actually reaches 9 or higher, but adding one dosage of calcium chloride would not hurt if you think it will make a difference. Try using the high range pH tester if it is available rather than the wide range pH tester since you know the pH is above 7.7; the HRPH test may give you a more precise color indicator.

No, pure calcium chloride would not have brought down the KH by anywhere near that much, that is a 3dKH change. For calcium to reduce KH (HCO3-), then this compound would need to be stripped of its hydrogen cation (H+) to make a carbonate (CO32-) and the carbonate is what gets neutralized by calcium.

To create the carbonate (CO32-), then there has to be one of 3 actions to occur: 1) an addition of a hydroxide (OH-); 2) consumption of a hydrogen cation (H+) directly striped from the bicarbonate (HCO3-); 3) addition of a hydrogen cation (H+) due to an acid.

Pure calcium chloride does not trigger these 3 events to occur unless the particular manufactured product being used has a slightly lower pH than pure calcium chloride; if it was lower, it would be negligible.


Rain is very acidic and the addition of this rain is like adding an acid, that is adding hydrogen cations (H+), to the water.

Rain effects everyone's pond different since the pond's volume makes a tremendous difference due to chemical dilution. A 500gallon pond with a 7 dKH has half the volume of alkalinity when comparing this to a pond with a 1,000 gallon pond with a 7 dKH. So, a 1 inch rain would have a much bigger impact on the 500 gallon pond, whereas a 1 inch rain would barely put a dent into a 1,000 gallon pond.


KH is constantly being consumed depending on your pond's bioload as well. Bioload includes your fish stock density, presence of organics, presence of algae and other plants, and the efficiency of the biological filtration system and including other contaminants such as rain.
 

crsublette

coyotes call me Charles
Joined
Oct 23, 2011
Messages
2,678
Reaction score
1,100
Location
Dalhart Texas
Hardiness Zone
6a
Any significant water changes will also dilute the KH and the extent of change would be determined by pond volume and water change volume.
 

crsublette

coyotes call me Charles
Joined
Oct 23, 2011
Messages
2,678
Reaction score
1,100
Location
Dalhart Texas
Hardiness Zone
6a
Cdsdave said:
I just tested my levels and my KH is down to 4 from 7? Could the calcium chloride have brought it down? This morning my WRPH was 8.2 now at 3:45 it's up past the 8.4 mark closer to the 8.8 range (similar to the earlier photo I submitted). We did get a brief downpour last night. I am going to add 4 oz. of baking soda to raise the KH up. Another interesting thing is my GH has gone from 3 to 16!!! Good I suppose but how did that happen? The calcium? I will test PH again after dinner and see if today was a fluke.

It's anybodys best guess. I am not a chemist. I just know what I know from experimenting in my pond.

My best guess is that it was a combination of the rain and possibly other stuff in the water.

Throughout the day, algae consumes inorganic carbons which can cause the pH to go up as evening approaches.... Do you have much noticeable algae?? What's your pond's volume??
 

crsublette

coyotes call me Charles
Joined
Oct 23, 2011
Messages
2,678
Reaction score
1,100
Location
Dalhart Texas
Hardiness Zone
6a
crsublette said:
To create the carbonate (CO32-), then there has to be one of 3 actions to occur: 1) an addition of a hydroxide (OH-); 2) consumption of a hydrogen cation (H+) directly striped from the bicarbonate (HCO3-); 3) addition of a hydrogen cation (H+) due to an acid.

Bah, I knew that did not sound right. Doubled checked my literature. Scratch that #3. As far as I am aware, #3 is false. I was thinking of something else not related to carbonate.
 
Joined
Mar 19, 2013
Messages
138
Reaction score
43
Location
Southern New Jersey
Checked the KH again and it's still around 4. My pond is 2000 gal. And there is some algae present. Not floating green algae but murky greenish water algae. I've been using pond logics Ecofix (supposedly all natural bacteria) to help consume the dead algae and add oxygen. I added another dose of baking soda (about 5-6 oz.) to help raise the KH. My PH tested 8.2 this morning and 8.4 tonight. Go figure PH is back to normal and KH is crashing:). Haven't done any significant water changes in 2 weeks when I last back flushed my bio filter. I plan on doing that this week.
 

crsublette

coyotes call me Charles
Joined
Oct 23, 2011
Messages
2,678
Reaction score
1,100
Location
Dalhart Texas
Hardiness Zone
6a
Yep, in our pond context, all algae require an inorganic carbon, such as bicarbonate and carbon dioxide, to survive. It would not take much algae for it to change the pH.

Very good. KH is doing its job. From what you are describing, the raised KH from baking soda is equilibrating. Even though it is fast, it is not instant and still takes time to function.

A pH swing between 8.2~8.4 is very good although I bet the Ecofix is causing the pH to be higher than it should be. With a 4 dKH, the pH should actually be more like around 7.5~7.8, that is assuming little phosphates in the water and no other residuals in the water that can affect the pH.

A pH of 8.2~8.4 with a KH of 4 dKH does not make much sense so this is why I think there is much more going on in your pond water that we do not know nor understand. I don't think this is anything to be concerned about, but something to keep in the back of your head muddling around a bit.
 
Joined
Mar 19, 2013
Messages
138
Reaction score
43
Location
Southern New Jersey
I agree with the much more going on in the pond that's not understood. KH is still at 4 even after 8 oz. of baking soda. GH was 16 for the past 2 days so I'm assuming my test was correct for that. PH was again in the 8.0-8.4 range over the last 48hrs. Algae is still the same, a murky greenish brown. All other levels are normal. Ammonia, nitrites, and phosphate all in the 0 range.

Over the last few weeks I've been tackling a few different issues at a time. Too many variables going on to determine what's causing what and what's working. I'm going to work on the KH to get that up then move on to the algae issue. I'm sure in this heat the fish don't mind the water being murky:).

Thanks for all your help!!
 
Joined
Dec 24, 2020
Messages
36
Reaction score
12
Country
United States
Hi all. I used baking soda to raise my KH but now my PH is at 9.0. When I first did the baking soda my PH went up to the 8.4-8.6 range from 8.0. I've read where calcium chloride will lower the PH to 8.3 if baking soda has been used to raise the KH. My questions are what and where do I get calcium chloride( is it a salt?) and how much to use per 1000 gallons?
Hi I enlarged my pond with a new addition which is a little bit more than 2 months old. I connected my old pond of 2800 gallons with my new pond which is 7800 gallons giving me a total pond of 10,600 gallons. When I first took my PH readings everything was fine until the plants started growing and algae on all the rocks. My PH was 7.5 in the night after 10 PM and went up to 9 in the day after 10 AM. I was going crazy taking readings every couple of hours and through the night. I found out if you let nature do it's job with our putting any PH up or PH down or backing soda it will level off to the correct PH. Of course you have to have a decent filter and air in your pond and if you have all of that it will correct on it's own. It could take anywhere from 60 to 90 days. My pond corrected it's self in a little bit more than 2 months. I checked this afternoon and the PH was 7.5. So give it time as long as you have all your basses covered good air, filtration and plants nature will do it's job and correct the problem. Of course if things are dangerous like PH of 10 or more than you must take action to lower it. Other than that have patience.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

Forum statistics

Threads
30,785
Messages
508,605
Members
13,043
Latest member
cisifom

Latest Threads

Top